SPOP implemented. Hash table resizing for Sets and Expires too. Changed the resize policy to play better with RANDOMKEY and SPOP.

Issue with redis-client used in scripts solved, now to check if the latest argument must come from standard input we do not check that stdin is or not a tty but the command arity

When using the shutdown command with redis-cli the server saves the database and, if successful, silently closes the connection. The redis-cli tool did not correcty handle this EOF case in its readLine loop and was therefore infinitely looping - and eating 100% of the CPU - while waiting for some data which would never come.